Baby Growth Percentile Calculator
Enter your baby's age, sex, and weight or length to see roughly where they sit on the WHO growth charts. This describes size, not health: your pediatrician tracks the trend over time.
Growth percentile questions
- What is a baby growth percentile?
- A percentile compares your baby's size to other babies of the same age and sex. The 50th percentile is the median. Sitting at the 20th or the 80th is not better or worse, it simply describes where your baby falls in the range. These figures use the WHO charts for ages 0 to 12 months.
- Is a low or high percentile a problem?
- Not on its own. Pediatricians watch the trend over time, not a single number. A baby who tracks steadily along the 10th percentile is usually thriving. A sudden jump or drop across percentile lines is what prompts a closer look, so bring any concern to your provider.
- Which growth chart does this use?
- The WHO Child Growth Standards for ages 0 to 12 months, which describe how healthy breastfed and formula-fed babies grow. We interpolate between monthly checkpoints for in-between ages. Your pediatrician may use WHO or CDC charts depending on your country and your baby's age.
- How accurate is an online percentile calculator?
- It is an estimate from a compact table, good for a rough sense of where your baby sits. It is not a clinical tool and cannot replace the chart your pediatrician keeps and plots over time. Use it for reassurance or to frame a question, not for a diagnosis.